Impact of a Worksite Diabetes Prevention Intervention on Diet Quality and Social Cognitive Influences of Health Behavior: A Randomized Controlled Trial.

OBJECTIVE
To evaluate the impact of a worksite diabetes prevention intervention on secondary outcomes regarding the change in diet quality and components of the Health Action Process Approach (HAPA) theoretical framework.

DESIGN
Pretest-posttest control group design with 3-month follow-up.

SETTING
University worksite.

PARTICIPANTS
Employees aged 18-65 years with prediabetes (n = 68).

INTERVENTION
A 16-week group-based intervention adapted from the Diabetes Prevention Program.

MAIN OUTCOME MEASURES
Diet quality was assessed using the Alternative Healthy Eating Index 2010; HAPA components were assessed via written questionnaire.

ANALYSIS
Repeated-measures ANOVA compared the between- and within-group change in outcomes across time.

RESULTS
Significant difference occurred between groups for the change in consumption of nuts/legumes and red/processed meats postintervention and for fruits at 3-month follow-up (all P < .05); a significant increase in total Alternative Healthy Eating Index 2010 score occurred postintervention in the experimental group (P = .002). The changes in action planning, action self-efficacy, and coping self-efficacy from HAPA were significantly different between groups after the intervention; the change in outcome expectancies was significantly different between groups at 3-month follow-up (all P < .05).

CONCLUSIONS AND IMPLICATIONS
The worksite intervention facilitated improvement in diet quality and in planning and efficacious beliefs regarding diabetes prevention. Further research is needed to evaluate the long-term impact of the intervention.